Closures for laboratory glassware



Aprll 16, 1963 P. vARNEY 3,085,705

CLosUREs FOR LABORATORY GLAsswARE Filed sept. 29. 1960 'l/ FIG. 4

6 FIG. 5 6 FIG. 6

i JNVENTOR.

PHILIP L. VARNEY BYW-/ZL ATTORNEY 3,85,765 CLSURI'JS FOR LABGRATGRY GLASSWARE Philip L. Varney, Florissant, Mo., assigner, by mesne assignments, to Brunswick Corporation, a corporation of Delaware Filed ept. 29, 1960, Ser. No. 59,294 2. Claims. (Cl. 215 4l) This invention relates in general to closures and, more particularly, to a closure or stopper for laboratory glassware, such as culture tubes, test-tubes, specimen tubes, and the like.

At the present time, most biological laboratories, such as those servicing hospital and physicians otlices, use various types of culture tubes and specimen tubes, such as test-tubes and other generally cylindrical vialsl having open tops. Heretofore, it has been the practice to close the open end of such tubes by some form of stopper, such as a wadded cotton plug which is pushed down into the tube-mouth. However, since they are used once and then discarded, the total cost of cotton `for plugging is not an inconsiderable item in the average bacteriology laboratory. Labor costs for plugging and losses vfrom rapid drying of media are further drawbacks. Moreover, during sterilization cotton relea-ses volatile constituents which condense on glassware which is thereby rendered unsuitable as a container for many commonly used synthetic media.

Moreover, such `closures offer no protection for the external Vsurfaces of the tube in the region of the tubemouth against contamination or physical breakage during the course of use and handling.

lt is, therefore, the primary object of the present invention to provide a closure of the type stated which is capable of secure snugtitting disposition with different tubes of particular nominal size regardless of rather wide variations or tolerances in actual diameter.

It is another object of the present invention to provide a closure of the type stated which can be easily and quickly applied to, or removed from, laboratory glassware and will, nevertheless, form a secure tight seal when pressed down into place.

It is a further object of the present invention to provide a closure of the type stated which is economical and can readily be mass-produced.

With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawing (one sheet) FIG. 1 is an elevational view of a closure constructed in accordance with and embodying the present invention;

FIGS. 2 and 3 are sectional views taken along lines 2 2 and 3 3 of FIG. 1;

FIG. 4 is an elevational View of Va glass laboratory tube equipped with a closure constructed in accordance with and embodying the present invention;

FIG. 5 is a transverse sectional view 5 5 of FIG. 4; and

FIG. I6 is a fragmentary sectional view taken along line 6 6 of FIG. 5.

Referring now in more detail and by reference characters to the drawing, which illustrates a preferred ernbodiment of the present invention, A designates a closure molded as a one piece unit from a synthetic resin or so-called plastic such as polypropylene, polyethylene or the like, and integrally comprising a cylindrical side wall .i of relatively thin proportions and merging around its upper margin in an outwardly flaring frusto-conical annular shoulder 2 preferably provided around its surface with a serrated pattern to facilitate manual griptaken along line 3,085,765 Patented Apr. I6,

2.. ping. The shoulder 2, in turn, merges around its upper margin with an vinwardly relieved .frusto-conical charnfer 3 which is also provided with a matchingsurface pattern and is integrally joined to a transversely extending top wall 4l having ya concentric circular depression 5 in its top surface. The top wall 4 Iis integrally provided with a concentric cylindrical boss 6 which is annularly spaced from the upper portion of lthe side wall 1 by a flat-topped inverted annular channel 7 into which the upper margin or rim 8 of the glass tube T will lit, `as shown in FIG. v6.

Formed integrally with, and projecting inwardly from, the internal face of the side wall 1 is a plurality of thin faired tins 9 which extend inwardly along non-radial lines as shown in FIG. 2 and at their lower extremities taper outwardly as at 10, terminating a short distance above the lower margin of lthe -side wall 1, as best seen in FIG. 3.

In use, the closure A is slipped over the top of a piece of laboratory glassware, such as the glass tube T, and the tins 9 will center the closure A around the tube T as well as provide the necessary frictional contact to hold the closure securely in place. The upper margin or rim 8 will be firmly seated in the channel 7, as shown in FIG. 6, and a tight seal thereby eiected. The side -wall l will then extend protectively down externally `around the upper portion of the glass tube T and, by reason of its inherent resiliency and the added resiliency introduced by the tins 9, serves to cushion the upper end of the glass tube T from accidental shock and breakage.

The closures A can be economically molded and are capable of repeated re-use. Moreover, the closures A can be cleaned and, if necessary, sterilized very easily for re-use when desired.

It should be understood that changes `and mcdiiications in the form, construction, arrangement, and combination of the several parts of the closures for laboratory glassware maybe made and substituted for those herein shown `and described without `departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to` secure by Letters Patent is:

l. A cap-like closure -for open-ended tubes, said closure being formed of a somewhat resilient rubbery material and comprising a tubular skirt open at one end and closed at the other, said skirt having a cylindrical side wall which is provided with a straight cylindrical inwardly presented internal lface, said side wall being provided around its internal face with axially extending inwardly projecting flexible tins which are initially and permanently curved laterally with respect to a radial plane extending through the line `of attachment between each lin and the skirt Vso as to bear tangentially against the tube to which the closure is applied, said closed end being provided on its interior face with an annular groove having a llat transverse face for snug-fitting planar abutment against the mouth of said tube, said tins extending from the base of the groove and terminating a short distance above the lower margin of said skirt, said tins having a relatively constant thickness for a greater portion of their axial length and being tapered at their lower ends outwardly away from the longitudinal center-line of the caplike closure, said closed end also having a downwardly extending concentric cylindrical boss having a diametral size substantially smaller than that of the inside diametral size of the open end of the tube over which the cap-like closure ts into the mouth of said tube, whereby the upper portion of the cap-like closure may shift slightly in the transverse direction with respect to` the open-ended tube under impact while -substantially maintaining the closure-forming endwise abutment between the flat botire tom face of the annular groove and the mouth of said tube.

2. The cap-like closure for open-ended tubes of claim 1 wherein the ns are somewhat C-shaped in transverse cross-sectional contour.

References Cited in the le of this patent UNITED STATES PATENTS 1,919,811 Stonebraker July 25, 1933 4. Sacks Apr. 28, 1936 Morton June 23, 1942 Boxley Dec. 8, 1942 Ferguson May 8, 1951 Kundert Dec. 16, 1958 Marcel Aug. 2, 1960 FOREIGN PATENTS Austria Sept. 15, 1954 

1. A CAP-LIKE CLOSURE FOR OPEN-ENDED TUBES, SAID CLOSURE BEING FORMED OF A SOMEWHAT RESILIENT RUBBERY MATERIAL AND COMPRISING A TUBULAR SKIRT OPEN AT ONE END AND CLOSED AT THE OTHER, SAID SKIRT HAVING A CYLINDRICAL SIDE WALL WHICH IS PROVIDED WITH A STRAIGHT CYLINDRICAL INWARDLY PRESENTED INTERNAL FACE, SAID SIDE WALL BEING PROVIDED AROUND ITS INTERNAL FACE WITH AXIALLY EXTENDING INWARDLY PROJECTING FLEXIBLE FINS WHICH ARE INITIALLY AND PERMANENTLY CURVED LATERALLY WITH RESPECT TO A RADIAL PLANE EXTENDING THROUGH THE LINE OF ATTACHMENT BETWEEN EACH FIN AND THE SKIRT SO AS TO BEAR TANGENTIALLY AGAINST THE TUBE TO WHICH THE CLOSURE IS APPLIED, SAID CLOSED END BEING PROVIDED ON ITS INTERIOR FACE WITH AN ANNULAR GROOVE HAVING A FLAT TRANSVERSE FACE FOR SNUG-FITTING PLANAR ABUTMENT AGAINST THE MOUTH OF SAID TUBE, SAID FINS EXTENDING FROM THE BASE OF THE GROOVE AND TERMINATING A SHORT DISTANCE ABOVE THE LOWER MARGIN OF SAID SKIRT, SAID FINS HAVING A RELATIVELY CONSTANT THICKNESS FOR A GREATER PORTION OF THEIR AXIAL LENGTH AND BEING TAPERED AT THEIR LOWER ENDS OUTWARDLY AWAY FROM THE LONGITUDINAL CENTER-LINE OF THE CAPLIKE CLOSURE, SAID CLOSED END ALSO HAVING A DOWNWARDLY EXTENDING CONCENTRIC CYLINDRICAL BOSS HAVING A DIAMETRAL SIZE SUBSTANTIALLY SMALLER THAN THAT OF THE INSIDE DIAMETRAL SIZE OF THE OPEN END OF THE TUBE OVER WHICH THE CAP-LIKE CLOSURE FITS INTO THE MOUTH OF SAID TUBE, WHEREBY THE UPPER PORTION OF THE CAP-LIKE CLOSURE MAY SHIFT SLIGHTLY IN THE TRANSVERSE DIRECTION WITH RESPECT TO THE OPEN-ENDED TUBE UNDER IMPACT WHILE SUBSTANTIALLY MAINTAINING THE CLOSURE-FORMING ENDWISE ABUTMENT BETWEEN THE FLAT BOTTOM FACE OF THE ANNULAR GROOVE AND THE MOUTH OF SAID TUBE. 